FORUMS

New Xposed for Lollipop 5.0 Update Fixes Major Bugs

Senior Recognized Developer rovo89 has patched Xposed for Lollipop 5.0 to … more

Download Sony’s new AOSP-like concept for Xperia Z3

Over in our forums, Recognized Contributor Jozinek has posted a very … more

OnePlus 2 vs Moto X Style: Which is The Better Flagship?

Two big industry names have announced their newest flagship phones within the … more

Making Your Own Xposed Modules Is Easier Than You Think

Close to the heart of XDA is the Xposed Framework by Rovo89. Most of … more

[HOWTO] Re-flash stock kernel, after your device is rooted

113 posts
Thanks Meter: 75
 
By uskr, Senior Member on 12th May 2011, 03:33 AM
Post Reply Subscribe to Thread Email Thread
Hello everyone,

I saw this question over and over around so I decided to post a quick guide here.

After I installed the insecure kernel on my SGS2, to allow me to root, I did a series of quadrant tests. And after comparing 10 runs with the 10 runs I did prior to root, I ended up with the impression that I lost about 200-400 points per run. The tests were not entirely conclusive, since the margin is not big (compared with the total). Regardless, I still wanted to try to squeeze out every bit of performance I can out of this beast. That's when I decided to re-flash the original stock kernel.

What you will need, is basically the same thing you did to gain root, but with another kernel.

Make sure you know what you are doing. I am not responsible if you do it wrong and brick your phone.

1. First download the stock kernel:
You can find the stock kernels here: http://nma.usk.bz/sgs2.php

DO NOT UNTAR THE FILE. Leave it as it is.

2. Now open Odin and put your phone in Download mode
3. IMPORTANT: Make sure that "Auto Reboot" and "F.Reset Time" are check. And that EVERYTHING else is UNchecked.
4. Load the .tar file on the PDA field. Just click on "PDA" and open the file.
5. Click "Start"

Done, you are back to your stock kernel and will keep root. This does not revert what you already installed (su, SuperUser, busybox, etc).

If you have any questions, post it here.

UPDATES:
------------
- Added XWKE7 stock kernel (05/21/2011)
Last edited by uskr; 21st May 2011 at 07:38 AM.
The Following 21 Users Say Thank You to uskr For This Useful Post: [ View ]
 
 
12th May 2011, 03:43 AM |#2  
Raspster's Avatar
Senior Member
Thanks Meter: 17
 
More
Hi uskr, I think this may be the same file in this top post in this thread which is what I just flashed to but thanks for this anyway.


http://forum.xda-developers.com/show...056334&page=35


Quote:
Originally Posted by uskr

Hello everyone,

I saw this question over and over around so I decided to post a quick guide here.

After I installed the insecure kernel on my SGS2, to allow me to root, I did a series of quadrant tests. And after comparing 10 runs with the 10 runs I did prior to root, I ended up with the impression that I lost about 200-400 points per run. The tests were not entirely conclusive, since the margin is not big (compared with the total). Regardless, I still wanted to try to squeeze out every bit of performance I can out of this beast. That's when I decided to re-flash the original stock kernel.

What you will need, is basically the same thing you did to gain root, but with another kernel.

Make sure you know what you are doing. I am not responsible if you do it wrong and brick your phone.

1. First download the stock kernel: http://nma.usk.bz/files/I9100XWKDD_StockKernel.tar

DO NOT UNTAR THE FILE. Leave it as it is.

2. Now open Odin
3. IMPORTANT: Make sure that "Auto Reboot" and "F.Reset Time" are check. And that EVERYTHING else is UNchecked.
4. Load the I9100XWKDD_StockKernel.tar file on the PDA field. Just click on "PDA" and open the file.
5. Click "Start"

Done, you are back to your stock kernel and will keep root. This does not revert what you already installed (su, SuperUser, busybox, etc).

If you have any questions, post it here.

12th May 2011, 04:16 AM |#3  
uskr's Avatar
OP Senior Member
Thanks Meter: 75
 
Donate to Me
More
Thank you for pointing it out. I had a hard time finding it when I needed. Hope this helps more people out there.

This one is from the original stock rom downloaded from kies. I just extracted the zImage.
12th May 2011, 11:35 AM |#4  
vimto25's Avatar
Senior Member
Flag Burton-On-Trent,UK
Thanks Meter: 34
 
Donate to Me
More
I no this is not relevant To stock kernel but if i update my phone to newest firmware this will work the same way,?
also there is a overclock kernel out if i want overclock kernel after i update to new firmware i would need to flash the root kernel then flash the overclock kernel to beable to have my phone run newest firmware with overclock kernel that is rooted.?
Thanks
Sent from my GT-I9100 using XDA App
12th May 2011, 11:59 AM |#5  
walda's Avatar
Senior Member
Thanks Meter: 243
 
Donate to Me
More
When we update to XWKE1, flash the unsecure KDD Kernel, root, how do we get back to KE1 Kernel?

Can you point on how to extract it?
12th May 2011, 12:39 PM |#6  
hakkinenvthh's Avatar
Senior Member
Flag France
Thanks Meter: 11
 
More
Quote:
Originally Posted by walda

When we update to XWKE1, flash the unsecure KDD Kernel, root, how do we get back to KE1 Kernel?

Can you point on how to extract it?

+1
How can we extract only the kernel from a stock firmware?
12th May 2011, 12:50 PM |#7  
walda's Avatar
Senior Member
Thanks Meter: 243
 
Donate to Me
More
I googled a lot and figgured out that this way should be the right.

* Flash new Firmware via ODIN (.tar File)
* Root with old KDD Kernel
* Open the FW .tar File
* Delete all except "zImage"
* Flash new .tar file via Odin

That should it be. Am not sure but

Will try when i got 100% and backuped my sdcard
12th May 2011, 01:25 PM |#8  
hakkinenvthh's Avatar
Senior Member
Flag France
Thanks Meter: 11
 
More
So we have to delete all the files in the tar, except "zImage". I found a guide to do it, but for the *.rar, I tried with the *.tar but it didn't work
http://xona.com/2006/07/05c.html
12th May 2011, 01:28 PM |#9  
Member
Thanks Meter: 9
 
More
Thanks. The kernel I used to root I think introduced an intermittent mic issue during calls.. now I'm back to the standard kernel and no more issue.
12th May 2011, 04:49 PM |#10  
BuzzFuzz's Avatar
Senior Member
Flag Split - Croatia
Thanks Meter: 170
 
More
Thanks dude
Last edited by BuzzFuzz; 12th May 2011 at 05:33 PM.
12th May 2011, 05:27 PM |#11  
uskr's Avatar
OP Senior Member
Thanks Meter: 75
 
Donate to Me
More
The warning triangle should be gone.

Try to reflash again and see if it helps. Did you flash anything else?

Lastly, which "brand" is your phone? This is for the XEU branded phone. If you have O2 or Korean versions, you will need a different stock kernel. I can get them for you.

To check your brand, type on your phone: *#272*<your IMEI>#

You can find your IMEI number on: Menu -> Settings -> About Phone -> Status .

Read More
Post Reply Subscribe to Thread
Previous Thread Next Thread
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes